Current track-driven machines use an endless track and chain assembly to provide load distribution and propulsion within a track system. A track system typically consists of a track roller frame, a plurality of rollers, one or more idler wheels, a driving wheel or sprocket, and a chain assembly. The chain assembly consists of track shoes connected to links to form an endless loop which encircles the track roller frame, the idler wheel(s) and the driving wheel. The track system typically utilizes one or two idler wheels, which provide a reasonably low friction load point for the chain to bend around and also provide a guiding means to keep the chain from moving out of alignment. Such idler wheels may be a one piece cast design or a welded fabrication and are mounted to the track roller frame. Due to the harsh environment these machines are used in, the track system are typically made from steel or cast iron. In operation, a significant amount of noise and vibration is generated as a result of the idler impacting the track links through rotation of the track.
Some idler wheel designs known in the art utilize a resilient material between an outer track link engagement ring or tread ring and a central hub. The resilient material is positioned between these two members to dampen the impact as the tread ring comes in contact with the track links. Some of these designs utilize a rigid one piece tread ring. Although this design may provide some dampening of the impact between the tread ring and the track links, it does not provide sufficient dampening for other track system designs. Other idler wheel designs utilize an outer retaining ring rigidly connected to the tread ring, with the tread ring being either segmented or one piece, and a resilient member positioned between the tread ring and a hub. Still other track systems are designed to have the outer retaining ring contact the track link connecting pins or bushings, which results in unwanted noise and vibration caused by the impact of these members.
The present invention is directed to overcoming one or more of the problems as set forth above.